export default {
  //hex颜色转rgb颜色
  HexToRgb(str) {
    str = str.replace("#", "");
    var hxs = str.match(/../g);
    for (var i = 0; i < 3; i++) hxs[i] = parseInt(hxs[i], 16);
    return hxs;
  },
  //rgb颜色转hex颜色
  RgbToHex(a, b, c) {
    var hexs = [a.toString(16), b.toString(16), c.toString(16)];
    for (var i = 0; i < 3; i++) {
      if (hexs[i].length == 1) hexs[i] = "0" + hexs[i];
    }
    return "#" + hexs.join("");
  },
  //加深
  darken(color, level) {
    var rgbc = this.HexToRgb(color);
    for (var i = 0; i < 3; i++) rgbc[i] = Math.floor(rgbc[i] * (1 - level));
    return this.RgbToHex(rgbc[0], rgbc[1], rgbc[2]);
  },
  //变淡
  lighten(color, level) {
    var rgbc = this.HexToRgb(color);
    for (var i = 0; i < 3; i++) rgbc[i] = Math.floor((255 - rgbc[i]) * level + rgbc[i]);
    return this.RgbToHex(rgbc[0], rgbc[1], rgbc[2]);
  },
};

/**
 * 判断是否 十六进制颜色值.
 * 输入形式可为 #fff000 #f00
 *
 * @param   String  color   十六进制颜色值
 * @return  Boolean
 */
export const isHexColor = (color) => {
  const reg = /^#([0-9a-fA-F]{3}|[0-9a-fA-f]{6})$/;
  return reg.test(color);
};

/**
 * RGB 颜色值转换为 十六进制颜色值.
 * r, g, 和 b 需要在 [0, 255] 范围内
 *
 * @return  String          类似#ff00ff
 * @param r
 * @param g
 * @param b
 */
export const rgbToHex = (r, g, b) => {
  // tslint:disable-next-line:no-bitwise
  const hex = ((r << 16) | (g << 8) | b).toString(16);
  return "#" + new Array(Math.abs(hex.length - 7)).join("0") + hex;
};

/**
 * Transform a HEX color to its RGB representation
 * @param {string} hex The color to transform
 * @returns The RGB representation of the passed color
 */
export const hexToRGB = (hex, opacity) => {
  let sHex = hex.toLowerCase();
  if (isHexColor(hex)) {
    if (sHex.length === 4) {
      let sColorNew = "#";
      for (let i = 1; i < 4; i += 1) {
        sColorNew += sHex.slice(i, i + 1).concat(sHex.slice(i, i + 1));
      }
      sHex = sColorNew;
    }
    const sColorChange = [];
    for (let i = 1; i < 7; i += 2) {
      sColorChange.push(parseInt("0x" + sHex.slice(i, i + 2)));
    }
    return opacity ? "RGBA(" + sColorChange.join(",") + "," + opacity + ")" : "RGB(" + sColorChange.join(",") + ")";
  }
  return sHex;
};

export const colorIsDark = (color) => {
  if (!isHexColor(color)) return;
  const [r, g, b] = hexToRGB(color)
    .replace(/(?:\(|\)|rgb|RGB)*/g, "")
    .split(",")
    .map((item) => Number(item));
  return r * 0.299 + g * 0.578 + b * 0.114 < 192;
};

/**
 * Darkens a HEX color given the passed percentage
 * @param {string} color The color to process
 * @param {number} amount The amount to change the color by
 * @returns {string} The HEX representation of the processed color
 */
export const darken = (color, amount) => {
  color = color.indexOf("#") >= 0 ? color.substring(1, color.length) : color;
  amount = Math.trunc((255 * amount) / 100);
  return `#${subtractLight(color.substring(0, 2), amount)}${subtractLight(
    color.substring(2, 4),
    amount
  )}${subtractLight(color.substring(4, 6), amount)}`;
};

/**
 * Lightens a 6 char HEX color according to the passed percentage
 * @param {string} color The color to change
 * @param {number} amount The amount to change the color by
 * @returns {string} The processed color represented as HEX
 */
export const lighten = (color, amount) => {
  color = color.indexOf("#") >= 0 ? color.substring(1, color.length) : color;
  amount = Math.trunc((255 * amount) / 100);
  return `#${addLight(color.substring(0, 2), amount)}${addLight(color.substring(2, 4), amount)}${addLight(
    color.substring(4, 6),
    amount
  )}`;
};

/* Suma el porcentaje indicado a un color (RR, GG o BB) hexadecimal para aclararlo */
/**
 * Sums the passed percentage to the R, G or B of a HEX color
 * @param {string} color The color to change
 * @param {number} amount The amount to change the color by
 * @returns {string} The processed part of the color
 */
const addLight = (color, amount) => {
  const cc = parseInt(color, 16) + amount;
  const c = cc > 255 ? 255 : cc;
  return c.toString(16).length > 1 ? c.toString(16) : `0${c.toString(16)}`;
};

/**
 * Calculates luminance of an rgb color
 * @param {number} r red
 * @param {number} g green
 * @param {number} b blue
 */
const luminanace = (r, g, b) => {
  const a = [r, g, b].map((v) => {
    v /= 255;
    return v <= 0.03928 ? v / 12.92 : Math.pow((v + 0.055) / 1.055, 2.4);
  });
  return a[0] * 0.2126 + a[1] * 0.7152 + a[2] * 0.0722;
};

/**
 * Calculates contrast between two rgb colors
 * @param {string} rgb1 rgb color 1
 * @param {string} rgb2 rgb color 2
 */
const contrast = (rgb1, rgb2) => {
  return (luminanace(~~rgb1[0], ~~rgb1[1], ~~rgb1[2]) + 0.05) / (luminanace(rgb2[0], rgb2[1], rgb2[2]) + 0.05);
};

/**
 * Determines what the best text color is (black or white) based con the contrast with the background
 * @param hexColor - Last selected color by the user
 */
export const calculateBestTextColor = (hexColor) => {
  const rgbColor = hexToRGB(hexColor.substring(1));
  const contrastWithBlack = contrast(rgbColor.split(","), [0, 0, 0]);

  return contrastWithBlack >= 12 ? "#000000" : "#FFFFFF";
};

/**
 * Subtracts the indicated percentage to the R, G or B of a HEX color
 * @param {string} color The color to change
 * @param {number} amount The amount to change the color by
 * @returns {string} The processed part of the color
 */
const subtractLight = (color, amount) => {
  const cc = parseInt(color, 16) - amount;
  const c = cc < 0 ? 0 : cc;
  return c.toString(16).length > 1 ? c.toString(16) : `0${c.toString(16)}`;
};

// 预设颜色
export const PREDEFINE_COLORS = [
  "#ff4500",
  "#ff8c00",
  "#ffd700",
  "#90ee90",
  "#00ced1",
  "#1e90ff",
  "#c71585",
  "#409EFF",
  "#909399",
  "#C0C4CC",
  "#b7390b",
  "#ff7800",
  "#fad400",
  "#5b8c5f",
  "#00babd",
  "#1f73c3",
  "#711f57",
];

/**
 * Mixes two colors.
 *
 * @param {string} color1 - The first color, should be a 6-digit hexadecimal color code starting with `#`.
 * @param {string} color2 - The second color, should be a 6-digit hexadecimal color code starting with `#`.
 * @param {number} [weight=0.5] - The weight of color1 in the mix, should be a number between 0 and 1, where 0 represents 100% of color2, and 1 represents 100% of color1.
 * @returns {string} The mixed color, a 6-digit hexadecimal color code starting with `#`.
 */
export const mix = (color1, color2, weight = 0.5) => {
  let color = "#";
  for (let i = 0; i <= 2; i++) {
    const c1 = parseInt(color1.substring(1 + i * 2, 3 + i * 2), 16);
    const c2 = parseInt(color2.substring(1 + i * 2, 3 + i * 2), 16);
    const c = Math.round(c1 * weight + c2 * (1 - weight));
    color += c.toString(16).padStart(2, "0");
  }
  return color;
};

/**
 * getCssColorVariable
 * @description 获取css变量的颜色值
 * @param colorVariable css变量名
 * @param opacity 透明度
 * @returns {string} 颜色值
 * @example getCssColorVariable('--el-color-primary', 0.5)
 * @example getCssColorVariable('--el-color-primary')
 * @example getCssColorVariable()
 */
export const getCssColorVariable = (colorVariable = "--el-color-primary", opacity) => {
  const colorValue = getComputedStyle(document.documentElement).getPropertyValue(colorVariable).trim();
  if (colorValue) {
    return opacity ? hexToRGB(colorValue, opacity) : colorValue;
  }
  return "";
};
